Byaruhanga, Joseph K.

Abstract [en]

Development of a nation is catalyzed and set on a firm foundation and path if the natural resources within the country are optimally exploited. The citizens are empowered economically, regions in the nation grow in terms of infrastructure and service provision and a lot of foreign exchange is saved; as this would have been spent in importation of raw materials. Currently, Uganda imports about 85% of the iron and steel products used in its industrial sectors. The country is endowed with iron ore deposits in the east and southwestern part, Figure 1. Each of these deposits is estimated to have about 50 million tonnes of ore reserve, with a rich grade of iron, and the lay unexploited. This paper reviews the current and traditional means of extracting and refining iron ores. The occurrences of iron ores, qualities and characterization methods have been reviewed. The mechanical, thermo-physical and thermodynamic properties plus the metallurgical extraction of the ore are also included. The aim is to understand the properties of iron and the behaviour of these when subject to various conditions, plus the technology involved in the exploitation of iron ores for iron and steel production. This will be used as a basis for the production of iron and steel raw materials for Ugandan industries, by exploiting the locally available iron ores in Uganda.

Muwanguzi, Abraham Judah Bumalirivu

Abstract [en]

Iron and its products, especially the various forms of steel, have been and still are a vital material in many sectors of life. It is utilized in many industrial activities ranging from production of heavy duty mechanical equipment to light electrical appliances and home appliances. With the world‟s iron ore consumption estimated to stand at 1.3 billion tonnes by 2025, exploitation of any existing natural deposits is of increasing importance to meet the demands of the expanding world economy. Large deposits of iron ore exist in Uganda in the eastern (Tororo) regions and south-western (Kisoro-Kabale) regions of the country. The ore deposits of Kisoro-Kabale consist of an iron-rich hematite grade with less deleterious impurities as compared to that of Tororo. Prospective quantification puts the deposits at 30-50 million tonnes of raw-ore reserves. To date the deposits lay unexploited, with small holder black smith activities taking place in the area. This work involves understanding the occurrence, quantity and quality of the ore plus its properties and characteristics in a bid to pave way for its exploitation for economic use in Uganda and beyond. Characterisation was done on the samples collected from the deposits, to establish its physical, chemical and metallurgical properties. Literature detailing the natural occurrence of the deposits plus the genesis of the parent rocks and ore and the prospective tonnage is included. The economic situation in Uganda as far as demand and consumption of iron and steel is concerned is also briefly highlighted. The chemical, physical and metallurgical characteristics that could facilitate the initial exploitation of the ore are examined with conclusive results from the representative samples examined. The results present Muko ore as a high grade of hematite with an Fe content averaging 68%. The gangue content (SiO

2+Al2O3) of 5 of the 6 samples investigated is < 4%, which is within the tolerable limits for the dominant iron production processes, with its S and P contents being < 0.1% and 0.07% respectively. Thus, Muko iron ore can be reduced in the furnace without presenting major difficulties. With respect to mechanical properties, Muko ore was found to have a Tumble Index value > 85 wt%, an Abrasion Index value < 4 wt% and a Shatter Index value < 2.5 wt%. This implies that the ore holds its form during the processes of mining, transportation, screening and descent when loaded in the furnace for reduction. Its reducibility index was found to be 0.868%/min. This is well within the desired reduction limits for the major iron reduction processes. It implies that a high productivity (in terms of iron reduced) can be realised in the reduction processes in a given period of time. Muko iron ore was found to meet most of the feed raw material requirements (physical, chemical and metallurgical) for the blast furnace and the major direct reduction processes (Midrex, HYL III and SL/RN). Furthermore, for those desired for sinter and pellet making. It can thus serve well as a feed raw material for smelting reduction and direct reduction processes.